20
6. Appendix A
A.1. Nominal Focal Spot Size - IEC 60336
RTI Slit Camera User’s Manual
1.0B
Table A-1 Nominal focal spot values according to IEC 60336. The dimensions shall be
measured with the slit method. Because of the multiplier 0.7 for focal spot sizes larger
than 0.3 there is a "jump" in permissible values of length in the table.
Nominal focal
Focal spot dimensions
spot value
Permissible value (mm)
f
Width
Length
0.1
0.10 - 0.15
0.10 - 0.15
0.15
0.15 - 0.23
0.15 - 0.23
0.2
0.20 - 0.30
0.20 - 0.30
0.25
0.25 - 0.38
0.25 - 0.38
0.3
0.30 - 0.45
0.45 - 0.65
0.4
0.40 - 0.60
0.60 - 0.85
0.5
0.50 - 0.75
0.70 - 1.10
0.6
0.60 - 0.90
0.90 - 1.30
0.7
0.70 - 1.10
1.00 - 1.50
0.8
0.80 - 1.20
1.10 - 1.60
0.9
0.90 - 1.30
1.30 - 1.80
1.0
1.00 - 1.40
1.40 - 2.00
1.1
1.10 - 1.50
1.60 - 2.20
1.2
1.20 - 1.70
1.70 - 2.40
1.3
1.30 - 1.80
1.90 - 2.60
1.4
1.40 - 1.90
2.00 - 2.80
1.5
1.50 - 2.00
2.10 - 3.00
1.6
1.60 - 2.10
2.30 - 3.10
1.7
1.70 - 2.20
2.40 - 3.20
1.8
1.80 - 2.30
2.60 - 3.30
1.9
1.90 - 2.40
2.70 - 3.50
2.0
2.00 - 2.60
2.90 - 3.70
2.2
2.20 - 2.90
3.10 - 4.00
2.4
2.40 - 3.10
3.40 - 4.40
2.6
2.60 - 3.40
3.70 - 4.80
2.8
2.80 - 3.60
4.00 - 5.20
3.0
3.00 - 3.90
4.30 - 5.60
Table A-2 Required magnification for focal spot slit radiograms in accordance with IEC
60336.
Nominal focal spot
Enlargement factor
value, f
E = n / m
f
0.4
E
3
0,5
f
1.0
E
2
1.1
f
E
1